Found it! Kinda tough searching for the correct file to modify. Think I'm learning.
In that file I just added an image "cc_fo_PP.gif" (just 4 small CC logo images that PayPal accepts, mine measures 73px by 46px) and chose to place it in folder
It it added to the tpl_ec_button.php code like this:
I can't imagine this is violating PayPal's TOS as it's not modify anything. It's an adjacent image ... like a style ... like background color or text size. If I'm wrong about this please advise. It looks pretty good too!
<div id="PPECbutton" class="buttonRow">
<?php // Modification START ?>
<img src="http://www.mydomain.com/store/includes/templates/classic/images/cc_for_PP.gif" alt="PayPal Accepts Credit Cards" />
<?php // Modification END ?>
<a href="<?php echo zen_href_link('ipn_main_handler.php', 'type=ec', 'SSL', true, true, true); ?>"><img src="<?php echo MODULE_PAYMENT_PAYPALWPP_EC_BUTTON_IMG ?>" alt="<?php echo MODULE_PAYMENT_PAYPALWPP_TEXT_BUTTON_ALTTEXT; ?>" /></a>